The purpose of the study is assess the potential to increase the use of renewable energy resources (biomass and geothermal energy) and combined heat and power in district heating generation. The study focuses on 19 district heating systems representing around 50% of Hungarian district heat consumption, relying on data provided by district heating companies and in-depth interviews with representatives of DH companies and professionals from biomass and geothermal industries. The study reviews the available biomass and geothermal resources, the technical characteristics and cost elements of different technologies, and estimates the costs of increasing the share of biomass and/or geothermal heating generation and CHP in the analysed district heating systems.